1. Field of the Invention
The present invention relates in general to a lubricant oil amount detector provided in an oil pipe in which lubricant oil is to be poured, and which is applicable to a vertical shaft type general-purpose engine to be loaded on a lawn mower or the like.
2. Description of the Prior Art
At first, the above-mentioned type of oil pipe in the prior art will be described with reference to FIGS. 6 to 8. As shown in these figures, an oil pipe 3 of a vertical shaft type engine in the prior art is fastened to a crank case cover 2 with a packing 10 pinched therebetween by means of bolts 4 or the like. The crank case cover 2 is provided with an oil passageway 11, and the level of lubricant oil of the engine and the level of oil within the oil pipe 3 are kept identical.
In addition, for the purpose of facilitating the pouring of lubricant oil when the engine is mounted on a lawn mower or the like, the oil pipe 3 has its pouring portion disposed above an upper surface of a fuel tank 5, and an oil cap 6 equipped with an oil gauge 6a is fitted in the oil pipe 3 by an easily detachable structure such as screw threads or the like.
Upon using the engine such as during normal lawn mowing work, before the engine is turned on an amount of lubricant oil is checked, and at that time, as shown in FIG. 8, the oil cap 6 is disengaged from the oil pipe 3 and the level of lubricant oil adhered to the oil gauge 6a equipped on the oil cap 6 is visually confirmed.
However, the above-described oil amount detector has shortcomings in that the confirmation of the oil amount is relatively troublesome, and hence, the seizure of an engine due to a shortage in oil caused by forgetting to inspect the oil amount occurs. Or, on the contrary, until a user is able to determine the consumption of lubricant oil of an engine as a matter of experience, unnecessarily frequent inspections have to be carried out.
Furthermore, since one end of an oil pipe is disposed above the top surface of a tank 5, which surface is located higher than an upper limit of the lubricant oil amount, in order to facilitate the pouring of oil into the pipe, an excessive pouring of lubricant oil can hardly be prevented. Therefore, the pouring and supplementing of a proper amount of lubricant oil is usually done by relying upon one's sense and experience.